Technical Field
The present invention relates to a manufacturing method of a liquid jet head that jets liquid droplets onto a recording medium for recording, a liquid jet head, and a liquid jet apparatus.
Related Art
In recent years, ink jet-type liquid jet heads have been used to eject ink droplets onto recording paper or the like to record texts and graphics or to eject a liquid material onto the surface of an element substrate to form a functional thin film. According to this system, a liquid such as an ink or a liquid material is guided from a liquid tank to a channel (ejection grooves) via a supply tube, and a pressure is applied to the liquid charged in the channel to eject the liquid from a nozzle communicating with the channel. Then, at the time of ejecting the liquid, texts and graphics are recorded or a functional thin film or a three-dimensional structure of a determined shape is formed while the liquid jet head or the recording medium is moved.
JP 2002-210955 A describes this kind of liquid jet head. FIG. 11 is a schematic cross-sectional view of a liquid jet head (FIG. 2 of JP 2002-210955 A). The liquid jet head includes a head chip 110 that ejects ink droplets and an ink manifold member 120 that supplies an ink to the head chip 110. The head chip 110 includes a channel portion 115. The channel portion 115 is surrounded by two drive walls not illustrated and are made of piezoelectric bodies, lower and upper substrates 111 and 113, a back plate 119, and a nozzle plate 118. The ink manifold member 120 includes an ink flow path 121 and an upper wrapping portion 122a. The upper wrapping portion 122a covers the upper substrate 113 of the head chip 110 and is joined to the back plate 119 of the head chip 110. The ink flowing into the ink flow path 121 is supplied to the channel portion 115 via an ink introduction opening 119a of the back plate 119. When the drive walls of the channel portion 115 are driven, the ink droplets are ejected from a nozzle hole 118a. 
A conductive member 117b penetrates to the upper substrate 113 in the thickness direction. The conductive member 117b is electrically connected to drive electrodes that are installed on the drive walls driving the channel portion 115. The upper wrapping portion 122a includes an electrode 123 penetrating in the thickness direction.
The electrode 123 is installed in a position corresponding to the conductive member 117b. The electrode 123 is electrically connected to the conductive member 117b via an electrode 117c formed on the upper surface of the upper substrate 113. The electrode 123 is further electrically connected to an electrode 124 formed on an upper surface 120a and is drawn out to a back surface 120b. Therefore, a drive waveform for driving the drive walls is input to the electrode 124 on the back surface 120b and is supplied to the drive electrodes on the drive walls through the electrode 123 installed on the upper wrapping portion 122a and the conductive member 117b installed on the upper substrate 113.
In the liquid jet head described in JP 2002-210955 A, the drive electrodes are formed inside the channel portion 115 by electroless plating method, a through-hole is opened in the upper substrate 113, silver paste or the like is charged into the hole to form the conductive member 117b, and the electrode 117c is formed on the upper surface of the upper substrate 113. In addition, a through-hole is also opened in the upper wrapping portion 122a and the electrode 123 is charged into the hole, and the pattern of the electrode 124 is formed on the ink manifold member 120 from the upper surface 120a to the back surface 120b. Accordingly, the electrode formation is extremely complicated.